1. Field of the Invention
The present invention relates to a shift-lock mechanism for an automatic transmission shifter for use in a vehicle, such as an automobile.
2. Description of the Related Art
Heretofore, an automatic transmission shifter for use in a vehicle such as an automobile has been widely known, and is disclosed, for example, in JP 2007-230424A. An automatic transmission shifter disclosed in this patent document comprises a swingable transmission range-switching member (guide bracket) coupled to an automatic transmission provided on a vehicle, a cable connecting the transmission range-switching member and the automatic transmission each other, and a selector lever (shift lever) detachably coupled to the transmission range-switching member. When the selector lever in a state of being coupled to the transmission range-switching member is moved to a selected one of a plurality of range zones (positions corresponding to respective ones of a plurality of shift ranges, such as a parking range and a drive range) within a gate, the transmission range-switching member is swingably moved along with the movement of the selector lever, and the cable is operated (pulled or pushed) depending on the swing movement, so that the automatic transmission is set to the selected range.
This type of automatic transmission shifter is provided with a shift-lock mechanism for, when once the selector lever is set to a parking range (P range) zone, locking the selector lever so as not to be unexpectedly moved to other range zone.
As an example of the shift-lock mechanism, there has been known one type as shown in FIGS. 18A and 18B. This shift-lock mechanism comprises a lock member 201 adapted to lock or unlock a transmission range-switching member 200 capable of swinging (rotating) in a frontward-rearward direction (X-Y direction in FIGS. 18A and 18B), and a solenoid 202 adapted to be operated in response to an operation of a brake device provided on a vehicle. The solenoid 202 includes a solenoid body 202a, and a plunger 202b adapted to be driven forwardly and backwardly with respect to the solenoid body 202a. The lock member 201 has an upper end formed with a contact portion 201a adapted to come into contact with the transmission-range switching member 200, and a lower end coupled to a distal end of the plunger 202b. Further, the lock member 201 has a pivoted portion 201b which is provided in an intermediate region thereof in an upward-downward direction to allow the lock member 201 to be swingably moved about the pivoted portion 201b so as to cause the contact portion 201a to be swingably moved in a rightward-leftward direction (W-Z direction in FIGS. 18A and 18B).
When a lever shaft 203 of the selector lever is moved into a parking range zone, this fact is detected by detection means (not shown), and the plunger 202b of the solenoid 202 is moved forwardly in response to the detection. Thus, as shown in FIG. 18B, the lock member 201 is swingably moved about the pivoted portion 201b in such a manner that the contact portion 201a is set to a position just rearward of the transmission-range switching member 200. In this state, the lock member 201 interferes with the transmission-range switching member 200 to preclude a possibility of a rearward swing movement thereof, so that the lever shaft 203 of the selector lever coupled to the transmission-range switching member 200 also becomes unable to be swingably moved in the frontward-rearward direction.
In this state, if a brake pedal serving as the brake device is depressed to initiate a braking operation, the plunger 202b is moved backwardly, as shown in FIG. 18A. Thus, the lock member 201 is swingably moved about the pivoted portion 201b in such a manner that the contact portion 201a is moved away from the position just rearward of the transmission-range switching member 200, laterally in the left direction in FIGS. 18A and 18B. Consequently, the transmission-range switching member 200 is placed in a swingably movable state.
However, in the above conventional shift-lock mechanism, the lock member 201 is coupled to the plunger 202b of the solenoid 202, and adapted to be swingably moved in response to the forward/backward movement of the plunger 202b. In this structure, during the forward/backward movement of the plunger 202b, a weight or an inertial load of the lock member 201 is imposed on the plunger 202b. Therefore, the solenoid 202 has to be a type capable of moving the plunger 202b forwardly and backwardly by a force greater than that required for swingably moving the lock member 201. Thus, the conventional shift-lock mechanism has a problem of an increase in size of the solenoid 202, resulting in an increase in overall size of an automatic transmission shifter.